/*
* ====================================================================
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* .
*
*/
package org.apache.hc.core5.http.message;
import java.util.Iterator;
import java.util.NoSuchElementException;
import org.apache.hc.core5.http.FormattedHeader;
import org.apache.hc.core5.http.Header;
import org.apache.hc.core5.util.Args;
/**
* {@link java.util.Iterator} of {@link org.apache.hc.core5.http.HeaderElement}s.
*
* @since 5.0
*/
abstract class AbstractHeaderElementIterator implements Iterator {
private final Iterator headerIt;
private T currentElement = null;
private CharSequence buffer = null;
private ParserCursor cursor = null;
/**
* Creates a new instance of BasicHeaderElementIterator
*/
AbstractHeaderElementIterator(final Iterator headerIterator) {
this.headerIt = Args.notNull(headerIterator, "Header iterator");
}
private void bufferHeaderValue() {
this.cursor = null;
this.buffer = null;
while (this.headerIt.hasNext()) {
final Header h = this.headerIt.next();
if (h instanceof FormattedHeader) {
this.buffer = ((FormattedHeader) h).getBuffer();
this.cursor = new ParserCursor(0, this.buffer.length());
this.cursor.updatePos(((FormattedHeader) h).getValuePos());
break;
}
final String value = h.getValue();
if (value != null) {
this.buffer = value;
this.cursor = new ParserCursor(0, value.length());
break;
}
}
}
abstract T parseHeaderElement(CharSequence buf, ParserCursor cursor);
private void parseNextElement() {
// loop while there are headers left to parse
while (this.headerIt.hasNext() || this.cursor != null) {
if (this.cursor == null || this.cursor.atEnd()) {
// get next header value
bufferHeaderValue();
}
// Anything buffered?
if (this.cursor != null) {
// loop while there is data in the buffer
while (!this.cursor.atEnd()) {
final T e = parseHeaderElement(this.buffer, this.cursor);
if (e != null) {
// Found something
this.currentElement = e;
return;
}
}
// if at the end of the buffer
if (this.cursor.atEnd()) {
// discard it
this.cursor = null;
this.buffer = null;
}
}
}
}
@Override
public boolean hasNext() {
if (this.currentElement == null) {
parseNextElement();
}
return this.currentElement != null;
}
@Override
public T next() throws NoSuchElementException {
if (this.currentElement == null) {
parseNextElement();
}
if (this.currentElement == null) {
throw new NoSuchElementException("No more header elements available");
}
final T element = this.currentElement;
this.currentElement = null;
return element;
}
@Override
public void remove() throws UnsupportedOperationException {
throw new UnsupportedOperationException("Remove not supported");
}
}